Lack of curd formation

[Veja]

Thanks for the help!  I'm going back into the kitchen!

[Veja]

Well I did it!  I'm not sure what I got, but it sure isn't mozzarella.  I'm not sure it's even cheese.  At the end, I couldn't get a good stretch, but it did come together. then the last step was to put it in a cold salt water bath in the fridge.  What came out was a salty-otherwise tasteless  ball. 
Back to the drawing board.

[Veja]

AND BTW, when i tried to make ricotta from the whey-there was NO curd left!

[MrsKK]

Citric acid precipitated mozzarella doesn't have much flavor.  To get really good fresh mozz, you need to make a cultured version.

Not getting any ricotta means that the proteins were all bound up in the mozzarella, so at least you didn't waste anything.

While it doesn't have much flavor, the quick mozz usually melts well on pizza, so not a total loss.

[Lennie]

I've had almost no luck using junket rennet and storebought pasteurized milk.  Very poor curd formation at best, even when I double the amount.  I bought good rennet tablets and it works better, I still have to add double amount but it makes a nice curd in a reasonable amount of time.

As for acidified mozzarella, I had to add 2.5tsp of tartaric acid to get my pH right for mozzarella.  Since you precipitated all your whey protein, it might be that you had your pH too low.  Mozzarella has to be the right pH to stretch.